Time-course study of the early lysosomal responses to pollutants in mussel digestivecells using acid phosphatase as lysosomal marker enzyme

摘要

Lysosomal biomarkers are early warning signals of the biological effects caused by environmental pollutantsbut the promptness of lysosomal responses to pollutants has not been investigated yet. This work is aimed todetermine the response-time of digestive cell lysosomes in mussels exposed to metals and hydrocarbons.Mussels, Mytilus galloprovincialis, were exposed, under laboratory conditions to Cd and to the water-accommodated fraction of a lubricant oil. One mussel per experimental group was sacrificed and processedevery hour from 0 h to 30 h. Changes in AcP activity, immunoreactivity and LMS test based on AcPhistochemistry, discriminates significantly control and exposed mussels within 5 h exposure. The presentresults suggested that after 15-20 h exposure digestive cell loss might be accompanied by increased AcPactivity (extralysosomal) without a parallel increase in the levels of immunoreactive AcP protein, especiallyafter Cd-exposure. The reduced labilisation period of lysosomal membrane constitute a cost effective earlywarning signal that, however, is not necessarily correlated with the exposure time. The routine application ofimmunochemical techniques deserves more research efforts before its implementation although, thesetechniques are very valuable to understand and interpret correctly lysosomal responses to pollutants.